One type of current depth camera is a structured light depth camera, which utilizes an infrared light source to emit patterned infrared light forming specific patterns when reaching an object surface, and utilizes an infrared sensor to detect reflected infrared light from the object surface for generation of an infrared image. The depth camera subsequently obtains a depth map by analyzing the infrared image. The structured light depth camera has an advantage that the depth map obtained thereby is relatively accurate. However, when objects in a field of view of the depth camera is far away from the depth camera, operational power of the infrared light emission is required to be increased so as to ensure successful reflection of the patterned infrared light by the object back to the structured light depth camera. Therefore, a drawback of higher power consumption is inevitable.
Another type of current depth camera is a stereoscopic depth camera, which utilizes two color sensors for generation of color images at different angles of view and which obtains a depth map by analyzing the color images thus generated. Since the stereoscopic depth camera is not required to emit infrared light, power consumption of the stereoscopic depth camera is smaller than that of the structured light depth camera. However, when a feature of a large plane is in the field of view of the stereoscopic depth camera, the number of edge pixels obtained from the color images which are captured by the stereoscopic camera is insufficient for effectively discerning a distance between the feature and the stereoscopic depth camera.